The science behind power naps

When pilot André Borschberg flew solo for 4 Days 21 Hours 52 Minutesfrom Nagoya in Japan to Hawaiiin the world’s first solar-powered plane, he only slept for twenty minutes at a time.

This is perhaps a more extreme scenario than most of us would find ourselves in, but an excellent example of how the power nap can help you to feel more alert and focused.

But how does it work? Do you love the idea but worry that instead of a quick rest, you’ll wake up hours later feeling groggy and disorientated?

We explore the science behind the power nap and share advice from leading sleep experts about how to plan your perfect rest.

How the power nap works

There are five stages of sleep.

As you first sink into sleep your eye, jaw-muscle movement, rate of respiration and your electrical brain activity all slow. This stage lasts up to ten minutes.

Stage two takes another ten minutes. It’s where your body gets ready for slow-wave sleep by further relaxing the muscles and lowering temperature. This sleep is light but restful.

In stage three the extremely slow waves (delta waves) begin, although at this stage they are still interspersed with faster smaller waves.

By stage four the brain almost exclusively produces delta waves. Stages three and four comprise ‘deep sleep’. In this deep sleep there is almost no eye movement or muscle activity.

Stage five is REM. This is where dreaming is most intense.

This cycle repeats every 90 to 120 minutes but most experts agree that a power nap should coincide with the first two stages, lasting approximately twenty minutes.

Sara Mednick, Ph.D., a scientist at the Salk Institute for Biological Studies who is at the forefront of napping research describes these first two stages “like a welding machine”. “When you wake up, your neurons perform the same function as before, but now faster and with more accuracy.”she says.